3D hierarchical rose-like Ni₂P@rGO assembled from interconnected nanoflakes as anode for lithium ion batteries

Abstract

In recent years, anode materials of transition metal phosphates (TMPs) for lithium ion batteries have drawn a vast amount of attention, due to their high theoretical capacity and comparatively low intercalation potentials vs. Li/Li+.

Key Parameter Optimization for the Continuous Synthesis of Ni-Rich Ni–Co–Al Cathode Materials for Lithium-Ion Batteries

“…SEM images (Figure a–c) illustrated high monodispersion and the spherical shape of precursor particles. Clear diffraction peaks and the absence of impurities from XRD patterns (Figure d) demonstrate typical solid-solution nature of as-prepared precursors. , In addition, high-resolution TEM (HRTEM) and the corresponding fast Fourier transform (FFT) and inverse FFT technology (Figure e,f) were also conducted to obtain detailed microstructure information of samples. The well-ordered P 3̅ m 1 phases with the representative plane directions including (001) and (110) could be clearly observed in the selected region of grains, further confirming the hexagonal crystal structure of precursors, which is consistent with XRD results. , As expected, at a pH value of 11.0, the obtained precursor has a relatively large particle size with narrow size range and a desired atom composition nearly close to the target value (Figure g,h).…”

“…Clear diffraction peaks and the absence of impurities from XRD patterns (Figure 2d) demonstrate typical solid-solution nature of as-prepared precursors. 33,34 In addition, high-resolution TEM (HRTEM) and the corresponding fast Fourier transform (FFT) and inverse FFT technology (Figure 2e,f) were also conducted to obtain detailed microstructure information of samples. The well-ordered P3̅ m1 phases with the representative plane directions including (001) and (110) could be clearly observed in the selected region of grains, further confirming the hexagonal crystal structure of precursors, which is consistent with XRD results.…”

Advances in metal phosphides for sodium‐ion batteries

“…Nickel phosphides have been considered as a class of promising anode materials for SIBs owing to their abundant resources, high theoretical‐specific capacity, and high electronic conductivity 23,30,76,77 . Specifically, Ni 2 P and NiP 3 have received extensive attention and been explored as promising anode electrodes during the past few years, which achieve impressive Na storage performance for SIB application.…”

“…Nickel phosphides have been considered as a class of promising anode materials for SIBs owing to their abundant resources, high theoretical-specific capacity, and high electronic conductivity. 23,30,76,77 Specifically, Ni 2 P and NiP 3 have received extensive attention and been explored as promising anode electrodes during the past few years, which achieve impressive Na storage performance for SIB application. The theoretical-specific capacity of hexagonal Ni 2 P (Figure 9A) is as high as 530 mA h g -1 , derived from the conversion reaction of Ni 2 P + 3Na + + 3e -→ 2Ni + Na 3 P. [78][79][80][81] NiP 3 shows a much higher theoretical capacity of nearly 1590 mA h g -1 , low redox potential of nearly 0.5 V, and a high tap density of 4.21 g cm -3 .…”

“…However, MPs also suffer from some problems, such as severe volume expansion and sluggish diffusion kinetics, thus leading to electrode pulverization and rapid capacity decay during cycling 22 . To address these issues, a diversity of impressive modification strategies have been proposed and systematically investigated, including (i) designing ingenious nano‐micro structure (e.g., sandwich‐like Ni 2 P nanoarray, 20 3D hierarchical rose‐like Ni 2 P@rGO, 23 and ultrathin few‐layer GeP nanosheets 24 ), which possesses plenty of space for volume expansion and increases the contact area between electrolyte and electrode materials to promote the diffusion of Na + and improve the stability of electrodes during the sodiation/desodiation processes; (ii) mixing with conductive carbonaceous materials (e.g., CuP 2 /C composites, 25 Sn 4 P 3 /reduced graphene oxide nanohybrids, 17 and carbon‐coated CoP 3 nanocomposites 26 ) to buffer volume variations and increase electrical conductivity of the electrodes; (iii) doping elements to improve the electrical conductivity of the electrodes (e.g., sulfur‐doped CoP 27 ). At present, combining multiple strategies to synergistically improve the performance of SIBs, such as nanochain‐like structure composed of hollow yolk‐shell Sn 4 P 3 @C nanospheres, 28 P doped onion‐like carbon layers coated FeP, 29 core‐shell Ni 2 P@carbon, 30 flower‐like Fe‐doped CoP, 31 cross‐linking hollow carbon sheet encapsulated CuP 2 nanocomposites, 32 and so on, has become the mainstream.…”